Chapter 7 - Traffic Calming Effects on Transit

Introduction

This chapter is based on Phase II of the TCRP H-4D project research program sponsored by the Federal Transit Administration. The Phase II report, “Transit-Friendly Streets: Design and Traffic Management Strategies to support Livable Communities” (TCRP Report 33), discussed the relationship between transit and streets. It emphasizes that the design and management of streets can affect the livability of communities. The report presents street design and traffic management strategies being used in cities throughout the United States.

The United States began to favor the automobile heavily in the 1950’s. This slowly disabled community streets from providing a safe place to walk, catch a bus or train, shop, or socialize. Because of this earlier trend, transportation agencies recognized that neighborhoods and central business districts were now dealing with fast-moving traffic encouraged by wider streets and narrower sidewalks. This also made it more difficult for transit agencies to provide service that was both efficient and convenient for the rider.

In the interest of maintaining a livable community, transportation agencies have recently began to redirect their efforts toward combining traffic and transit matters with transportation, community growth, and environmental issues. According to the Transit Cooperative Research Programs (TCRP), “success is produced by communities working in partnership with transit and transportation agencies to shape both street design and management to better balance the needs of a variety of users.”¹

Designing streets for the needs of all users, whether they are pedestrians, bicyclists, or transit users, will improve the livability of a community. Also according to the TCRP Report 33, the transit user can especially rely on better management and design of streets to ensure a more reliable service “by reducing the competition for street space among cars, buses, or light rail vehicles.” It can improve safety and accessibility for transit patrons.¹

Transit-Friendly Streets

Transit friendly streets are streets where transit use is made more efficient and convenient and the street is made less efficient and convenient for automobiles. Streets designed for the needs of all users, as stated earlier, are important to the concept of a transit-friendly street. According to the TCRP Report 33, transit-friendly streets accomplish the following three goals:²

• They establish a clear priority for transit vehicle operation with convenient, accessible transit stops.
• They reduce conflicts between cars and other vehicles, including reduction of vehicle speeds.
• They create a strong pedestrian orientation, including adequate circulation space, ease in crossing streets, and appropriate amenities, all of which contribute to comfort and convenience.

Traffic-Calming: Making Streets for Livable Communities

In Europe, the impacts of traffic calming on public transit have been discovered to be both positive and negative. The positive are as follows:³

• Improved Accessibility - Pedestrians can safely reach transit facilities without having to encounter fast-moving vehicles or wide streets that are difficult to cross.
• Improved Scheduling - Contention for street space between buses and vehicles is minimized.
• Improved Surroundings and Aesthetics - Traffic calming measures can allow more space for street side amenities such as planters, drinking fountains, bike racks, and sculptures.

In Europe traffic calming has expanded from local residential streets to main roads and commercial areas. This occurrence has brought some negative impacts on public transit, as follows:

• Increased Travel Time - Traffic calmed streets can increase travel time causing the bus service to become less efficient and appealing.
• Bus Route Relocation - Many times buses are relocated to areas outside of traffic calmed areas making traveling by bus less convenient for the rider.

Traffic Calming in the U.S. has, until now, been almost non-existent. In the past it only existed as areas designed to serve pedestrians and transit, excluding the car. Now cities such as Portland, Boston, and San Francisco have used traffic-calming measures to help turn their downtown areas into a more pedestrian friendly environment. There has been a growing effort to combine transit and traffic calming.

Design and Traffic Management Strategies for Transit-Friendly Streets

Case studies and general research done by the Transit Cooperative Research Program were used to develop general strategies for creating transit-friendly streets. They concentrated on street design and traffic management strategies from a viewpoint of balancing the needs of people in transit, automobiles, bicycles, and on foot. These strategies can contribute to the overall livability of the community.

Strategy 1: Provide Adequately Sized Sidewalks

Distribution of space to vehicles and pedestrians is the main concern when designing a commercial street. An added concern is the types of vehicles using the commercial street. The development of a pedestrian-friendly environment will influence the decisions made towards transit and vehicle usage.

Sidewalk Widening: Like streets, sidewalks have many purposes. Aside from pedestrian walkways, they are also areas of social gathering. In order to accommodate the needs of all sidewalk users, sidewalks must be dimensioned for convenient placement of benches, bus shelters, trees, and other suitable amenities.

The width of a sidewalk is determined by dividing it into imaginary “lanes”:⁴

• Lane 1 is the area adjacent to a store window and is approximately 2-3 feet wide. It serves as a viewing space for window shoppers
• Lane 2 is at the curb where a 1 ½” foot boundary separates the people and existing trees, signs, etc.

The area between these two lanes is the designated “walking space.” This space is usually eight feet wide or equivalent to the amount of space needed for two pairs of pedestrians to pass each other with ease.

In order to balance the needs of pedestrians with those of vehicles on the street, it is important to know how specific vehicles are using the street. They may be using it for parking, deliveries, passenger drop off or pick up, or simply as thoroughfare. Based on these uses, the following actions can be taken to create more space for pedestrian use:⁵

• Eliminate on-street parking.
• Reroute or restrict traffic to specific hours or specific lanes.
• Calm traffic speeds to encourage traffic to divert to other routes.
• Give priority access to buses.

Sidewalk Bulbouts: Accommodating pedestrian, vehicular, and transit uses of a street does not require extensive modification which consume a lot of time and money. Sidewalks can be widened in any area that is congested or at intersections. Sidewalk extensions at these locations can be referred to as bulbouts, neckdowns, nubs, bus, bulbs, bump outs, or curb extensions.

Bus bulbs are sidewalk extensions that include a bus stop. The bulbs extend out through the parking lane until they border the travel lane, which allows buses to stop in the travel lane to drop off and pick up passengers. Being able to stop in the travel lane prevents weaving in and out of traffic and reduces potential conflicts between vehicles and buses. In essence, this reduces boarding and stagnant time of buses, and contributes to a more efficient transit service. Bus bulbs or bulbouts also reduce crossing distances for pedestrians and provide room for planting strips, street furniture, or even street cafes. These extensions also help meet ADA requirements at bus stops.

Strategy 2: Provide Amenities for Pedestrians and Transit Riders

The design of sidewalk space is as important as the design of street space. It is often thought, that transit stops do not have the needed amenities for riders, due to lack of space or resources.

Other studies referred to in the TCRP Report 33 describe the effects of amenities on a passenger’s experience and his transit choices. From a transit viewpoint, there are two ways to provide amenities. The most common way is to space bus and light rail stops along a street. Another is to place a few bus stops in a central location so that attractive passenger amenities can be concentrated in one area.⁶

Transit amenities located on sidewalks include:

• Bus shelters
• Seating
• Trees
• Telephones
• Light fixtures
• Trash receptacles
• Information kiosks
• Clocks
• Fountains, sculptures, and banners
• Drinking fountains
• Food vendors (in some cases)

In order to guarantee that these amenities make a street more comfortable and active, proper location and design is essential. For example, bus shelters without walls or with short canopies provide little protection for sun, rain, and wind and provide little leaning or sitting space. Also, seating may be wasted if placed too far from activity or if it faces the wrong way. When amenities are placed on bus bulbs, care must be taken not to block pathways to bus doors or block views to approaching buses, otherwise, the bus bulb will not function efficiently for riders and pedestrians.

Strategy 3: Create Priority Lanes for Transit Vehicles

The transit-only lane or transitway is defined in an ITE Journal article called Transitway: An Innovation in Public Transportation.⁷ The transitway is defined as a roadway or a lane of a roadway used by buses and other high occupancy vehicles (HOVS). It is one of the most common strategies used to improve transit efficiency in many locations including transit malls.

Transitways are not always an appropriate solution because it is difficult to keep private cars from using reserved bus lanes, especially when vehicles must occupy these lanes to make right turns. San Francisco is one location that has implemented transit-only lanes and studies show that they have only been effective when strictly enforced. Due to the significant amount of traffic control officers required for such enforcement, the city of San Francisco decided to try an alternative approach. On O’Farrell Street in Downtown, left sided transit lanes combined with a boarding island for bus passengers and usual enforcement, have increased the effectiveness of transit-only lanes.⁸

Another solution to preventing vehicles from entering transitway lanes is to introduce a “contraflow” system in which buses in one lane move in one direction while vehicles in the other lanes travel in the opposite direction. The downfall of this alternative is that it poses safety concerns for pedestrians who may not be expecting a vehicle coming from the opposite direction.

Strategy 4: Redesign Intersections and Modify Signalization

Signalization modifications and other design features at intersections can also have a positive effect on transit efficiency. Such measures can improve priority for transit but effects on pedestrians must be considered.

Intersection Design: An intersection’s configuration must consider the vehicle’s needs as well as the pedestrian needs. An example in which the pedestrian is often neglected are the curb radii. They are usually designed to make it easier for vehicles to turn thus making it inconvenient and dangerous for pedestrians to cross the intersection, because cars are turning in front of and behind them. Larger radii also encourage greater turning speeds and reduce the crossing time for pedestrians.

Narrowing the street width, by widening sidewalks along the full length of a street or just at intersections, can facilitate pedestrian crossing. As mentioned earlier, adding bus bulbs is a away to narrow the street while creating shortened crossing distances for pedestrians and safer waiting areas.

Signal Preemption: According to the TCRP Report 33, signal preemption is a system installed to hold a green light for transit vehicles or to change the light to green after a minimal period so that transit vehicles do not stop at an intersection. The technology used ranges from contacts on light-rail overhead wires to systems using radiowaves or soundwaves.

In 1988 signal preemption was used at 16 intersections in San Francisco. In this case, overhead wires in contact with coaches and light rail were used to change signals Analysis shows a 6 to 10 percent reduction in transit delay.

Priority Green: With this signalization system, buses and trams are given priority at intersections, that is, transit vehicles get a green light before automobiles do. Because transit vehicles get a head start on automobiles queuing at a red light, they merge more easily back into traffic. This system is quite common in Europe and has been found not only to be effective on speeding up transit service, but has had a negligible effect on private car traffic. Journey times for trams and buses are now shorter and the speeding up of service often allows for one less vehicle to be deployed on a specific line, thus saving the transit operator money.

Transit priority signals can be activated by the vehicle of the transit driver. If the transit vehicle is traveling in a dedicated lane, a detector that triggers the traffic signal to change can be placed in the pavement. If the transit vehicle is moving in mixed traffic, the driver can trigger the signal from the vehicle. According to the Ontario Ministry of Transportation, “this method is most effective when it is used at intersections where transit vehicles face routine delays because of heavy volumes of automobile traffic or where transit vehicles need to make left turns against steady oncoming traffic.”

Queue Jump: A queue jump is used to provide transit priority at intersections by narrowing streets at transit stops to prevent automobiles from passing buses and to reduce the danger to pedestrians crossing the street to the bus stop. The easiest way to implement this strategy is to modify a right-turn lane with signage that reads “right turn only except buses and then place a small bay on the other side of the intersection for buses to reenter the flow of traffic. Transit planners believe that this technique is most effective on roadways with heavy volumes of automobile traffic.

References

1. Transit Friendly Streets: Design and Traffic Measurement Strategies to Support Livable Communities, 3.
2. Transit Friendly Streets: Design and Traffic Measurement Strategies to Support Livable Communities, Transit Cooperative Research Program, Report 33, 1998, 5.
3. Transit Friendly Streets: Design and Traffic Measurement Strategies to Support Livable Communities, 7.
4. Transit Friendly Streets: Design and Traffic Measurement Strategies to Support Livable Communities, 40.
5. Transit Friendly Streets: Design and Traffic Measurement Strategies to Support Livable Communities, 41.
6. Transit Friendly Streets: Design and Traffic Measurement Strategies to Support Livable Communities, 42.
7. Transitway: An Innovation in Public Transportation, ITE Journal, August 1996.
8. Transit Friendly Streets: Design and Traffic Measurement Strategies to Support Livable Communities, 43.

This chapter originally written by Michael Carmen, 2002, as part of a senior project.